Technical methods for energy-saving combustion transformation of coal-fired boilers
1、 Coal fired boiler flue gas waste heat recoveryThe flue gas temperature of industrial coal boilers is generally above 180 ℃, which not only pollutes the environment but also wastes valuable flue gas waste heat resources. The use of heat pipe heat exchange technology or burner waste heat recovery system can effectively recover some polluted flue gas waste heat resources, preheat boiler combustion air, or directly produce hot water.2、 Renovation of coal conveying equipment for coal-fired boilersAt present, layer combustion boilers burn raw coal, most of which are forward chain grate boilers. The original bucket type coal feeding device mixes blocks and final coal and piles them on the grate, hindering the boiler's intake and affecting combustion. Changing the bucket type coal feeding to layered coal feeding, using a gravity screen to disperse the raw coal and final coal from bottom to top, is beneficial for wind direction, improving combustion conditions, increasing coal combustion rate, reducing ash carbon content, and achieving a coal saving rate of 5% to 20%. Depending on the changes in furnace conditions, the energy-saving effect varies, and the worse the furnace conditions, the better the effect. Low engineering investment, good energy-saving effect, and fast recovery speed.3、 Oxygen rich combustion technology for coal-fired boilersUnder normal circumstances, when the flame temperature of the boiler is insufficient, the carbon content of the coal slag is high, the Grimm blackness level of the flue gas cannot meet the standard, the combustion efficiency of the boiler is not high, and the boiler output is insufficient, oxygen rich combustion technology can be considered to increase the oxygen content in the combustion air, make the fuel burn more fully, reduce the smoke emissions after combustion, increase the flame temperature and smoke blackness, and achieve energy savings of 5% to 15%, Increasing boiler output by more than 10%, oxygen rich combustion technology has good energy-saving and environmental benefits.4、 Transformation of combustion mode for coal-fired boilersSpray an appropriate amount of coal powder into the furnace from the appropriate position of the coal-fired boiler, and add an appropriate amount of suspended combustion on the basis of grate layer combustion, with an energy-saving rate of about 10%. It should be noted that the amount, speed, and position of coal injection should be appropriately controlled, otherwise it will increase the smoke exhaust blackness and affect the energy-saving effect. In fuel, gas, and coal powder boilers, the use of new energy-saving burners has replaced outdated burners. The effect of the renovation is still related to the original equipment status, with the worse the original condition, generally reaching 5% to 10%.5、 Energy saving renovation methods for coal-fired boiler archesBy adjusting the shape and position of the furnace arch reasonably, the combustion state of the burner can be improved, combustion efficiency can be increased, and coal consumption can be reduced.6、 Energy saving renovation technology for auxiliary equipment of coal-fired boilersThe operating parameters of the blower and induced draft fan are directly related to thermal efficiency and energy consumption. By adopting appropriate speed regulation technology and adjusting the drum and induced draft according to the load requirements of the boiler burner, the boiler combustion operation can be maintained in the optimal state. On the one hand, it can save coal for the boiler, and on the other hand, it can save energy consumption for the fan.7、 Regular cleaning of boiler burners and economizer soot and dirt can achieve energy conservationAfter a period of operation, coal-fired boilers will accumulate ash and scale on the inner and outer walls of the burner, tube bundle, smoke chamber, and economizer, seriously affecting the boiler output and thermal efficiency. Establishing a regular cleaning system for ash and scale accumulation in boiler burners can reduce thermal resistance, increase heat transfer efficiency, ensure good boiler operation, and achieve energy-saving effects.8、 The renovation of the combustion control system of coal-fired boilers can achieve energy conservationIn the energy-saving renovation of industrial boiler combustion control system, one method is to adjust the coal feeding rate, water feeding rate, blast rate, and induced air flow rate in real time according to the boiler load requirements, so that the boiler combustion is often in a good operating state. Transforming the original burner manual or semi-automatic control into fully automatic control has a very good energy-saving effect on boilers with large load changes and frequent changes, usually up to about 10%. For fuel and gas boilers, the energy-saving effect is consistent and the economic benefits are high.The combustion energy-saving transformation technology and methods of coal-fired boilers can not only save costs, improve thermal efficiency, and prolong the service life of boilers, but also meet the technical requirements of boiler environmental protection to a certain extent, which can be said to be a win-win situation.